Quick-fixing device for a watchband

ABSTRACT

A self-aligning device for attaching a watchband comprises a watch case having a cusp that includes means for positively aligning the end of a retractable spring-bar prior to retracting the end for engagement with the hole in the watch case cusp. The self-aligning device includes a semi-cylindrical depression in the lower surface of the watch cusp that engages the extended spring-bar for alignment with the engagement hole in the cusp, and may also include a second semi-cylindrical depression in the lateral face of the watch cusp to guide the retracted spring-bar from the alignment depression to the engagement hole in the watch case cusp.

The present invention relates to a quick-fixing device for a watchbandand more particularly to a fixing device comprising an elastic bar oneelement of which is firmly connected to an operating button disposedunder the watchband whose operation permits the introduction or removalof the bar, corresponding openings being formed in one of the cusps of awatchcase.

Fixing devices for watchbands are intended to permit easy replacement ofwatchbands. Up to now watchbands were replaced for reasons of wear oraging and these replacements were not very frequent so that the use of aquick-fixing device was not required. For several years manufacturershave proposed several types of watchbands for the same watch andreplacements are becoming much more frequent to adapt differentwatchbands as one pleases depending on the use, the color or thefashion. It has thus become necessary for users to be able to effect apractical and quick replacement of the watchbands themselves.

Numerous forms of fixing devices for watchbands are known but they allpresent disadvantages. The best known and most widespread forms consistof a simple elastic bar, but these forms present the essentialdisadvantages of being impractical because the removal or introductionof the bar generally necessitates the use of a tool. With these knownforms it is possible to remove or introduce the bar using a fingernailbut the small dimension of the elements makes this very impractical andtherefore inadequate for frequent replacements. Examples are known,which do not include introduction openings or positioning openings andthe fixing of the bars often requires several attempts.

The objective of the present invention is thus to remedy thedisadvantages of the known forms.

The objectives are reached by the principle of the invention asdescribed by claim 1.

According to the principle of the invention, the quick-fixing device fora watchband comprises an elastic bar which includes two elements slidingin one another and subject to the action of an elastic compressionmember. The ends of the bar are intended to cooperate, in the serviceposition, with holes formed in the cusps of the watchcase. This formpresents numerous advantages, the most important one being the fact thatthe easy action of the button enables an introduction and an easy andpractical disengagement of the bar which, consequently, leads to a veryhandsome replacement operation of the watchband elements for every user,which is especially important for frequent replacements. Anotherimportant advantage is the fact that the operating button is disposed onthe underside of the watchband, i.e. between the watchband and the wristof the user, eliminating any risk of unintentional action. According tothe invention, the cusps comprise openings with forms facilitating thepositioning and the introduction of the bar. The principle of theinvention further present the advantage that due to the easiness of theintroduction and the disengagement of the bar the device can be used asa lock by simply modifying the case.

The adjoined drawings illustrate the principle of the inventionschematically and by way of example.

FIG. 1 is a sectional view of the quick-fixing device for a watchband,in a closed position.

FIG. 2 is a bottom view of the fixing device in a closed position.

FIG. 3 is a sectional view of the fixing device in a positioningposition.

FIG. 4 is a sectional view of the fixing device in an intermediateintroduction position.

FIG. 5 is a side detail of one of the cusps constituting the fixingdevice.

Referring first to FIGS. 1 and 2, an elastic bar comprises two mainelements, shaft 1 and rod 2 which is slidingly mounted in cylindricalhole 3 formed in shaft 1. Elastic member 4 is mounted in cylindricalhole 3 and acts when compressed against the bottom of the cylindricalhole and against the inside end of rod 2. Elastic member 4 can comprisea spring. Shaft 1 is mounted in one of the ends of one of watchbandelements 5. Shaft 1 includes rod 10 whose end has a semispherical shape.Rod 10 is intended to cooperate with hole 11 formed in the insidevertical face of a cusp with hole 12 of watchcase 18. Outside parts 14of rod 2 is intended to cooperate, in a closed position, with hole 13formed in the inside vertical face of a cusp with openings 15.Positioning opening 17, of semicylindrical shape, is formed in the lowerhorizontal face of cusp 15. End 14 of rod 2 is intended to cooperatewith positioning opening 17 in the positioning position. Introductionopening 16, of semicylindrical shape, is formed in the inside verticalface of cusp 15. This introduction opening 16 is formed from the lowerhorizontal face of cusp 15 to hole 13.

Operating rod 8 is fixed on rod 2 perpendicular thereto. The operatingrod is disposed in opening 6 formed in shaft 1 and in opening 7 formedin watchband 5. The end of operating rod 8 includes operating button 9disposed under watchband 5 and intended to be operated by a user'sfinger for example.

FIG. 3 shows the positioning position, i.e. the position in which theuser fits the end of a watchband element in the cusp of the watchcase.The first phase consists in introducing rod 10 in hole 11 of cusp 12.Pressure of a finger on watchband 5 or on button 9 causes end 14 of rod2 to be disposed in positioning opening 17 formed in the lowerhorizontal face of cusp 15.

The positioning opening permits the user to find the proper introductionposition easily blind.

FIG. 4 shows the introduction position. In this position rod 10 remainsintroduced in hole 11 of cusp 12. Button 9 is operated by a finger so asthe make rod 2 slide toward the inside, thereby compressing elasticmember 4 disposed in cylindrical hole 3. Pressure simultaneously exertedon the button upward causes end 14 of rod 2 to be introduced andmaintained in position in intermediate introduction opening 16 until itis introduced in hole 13, i.e. in the closed position shown in FIGS. 1and 2.

Referring to FIGS. 1 and 2, the watchband is removed by operating button9 so as to disengage end 14 of rod 2 from hole 13.

FIG. 5 shows in detail positioning opening 17 formed in the lowerhorizontal face of cusp 15 firmly connected to watchcase 18, andintroduction opening 16 formed in the inside vertical face of cusp 15from the lower horizontal face of the cusp to hole 13.

The materials used for realizing the fixing device are independent ofthe principle of the invention. The shaft, rod, cusps and watchcase canbe realized in ferrous or non-ferrous materials, precious materials suchas gold for example, as well as plastics, composite or ceramic materialsby way of example.

The materials used for realizing the watchband are independent of theprinciple of the invention, the fixing device being adaptable to allwatchbands realized in a great variety of materials, taking account ofthe fact that if the watchbands are realized in nonworkable materials aworking clearance must be provided between the watchband and the cusps.

I claim:
 1. A watch case having a feature for aligning a retractablespring-bar comprising:a watch case including a cusp, said cusp includingan engagement hole for engagement with the retractable spring-bar; meansincorporated into said cusp to positively align the spring-bar in itsextended condition prior to engagement of the spring-bar with saidengagement hole; whereby a watchband may be quickly attached to thewatch case by first aligning the spring-bar with the engagement hole andthereafter retracting the spring-bar and engaging the engagement hole.2. The watch case of claim 1 wherein the means for aligning thespring-bar comprises means for engaging predominantly the lateralsurface of said spring-bar.
 3. The watch case of claim 2 wherein saidcusp further includes a lower surface;wherein the means for engagingpredominantly the lateral surface of the spring bar comprises analignment opening, said alignment opening comprising a substantiallysemi-cylindrical depression formed in said lower surface for engagementwith the spring-bar prior to retracting an end of the spring-bar forengagement with the engagement hole.
 4. The watch case of claim 3further including an introduction channel, said introduction channelcomprising a substantially semi-cylindrical depression formed in thelateral surface of said cusp and intersecting said alignment opening andsaid engagement hole.
 5. The watch case of claim 4 further including asecond cusp having an engagement hole, wherein said introduction channelhas a depth sufficient to permit an end of a retracted spring-bar topass from the alignment opening to the engagement hole when the otherend of said spring-bar is engaged in the engagement hole in said secondcusp.
 6. The watch case of claim 4 wherein the alignment opening andintroduction channel have radii approximately equal to the cylindricalradius of the end of the spring-bar.
 7. The watch case of claim 1further including a spring-bar having a means for manually retracting anend of said spring-bar, said spring-bar having semi-spherical ends.
 8. Awatch case comprising:a watch case including a plain and a self-aligningcusp said plain and self-aligning cusps having lateral faces comprisingsubstantially parallel opposing surfaces; the plain cusp including aplain hole normal to the lateral face of the plain cusp; the selfaligning-cusp including a self-aligning hole normal to the lateral faceof the self-aligning cusp and substantially collinear with the plainhole; the self-aligning cusp further including a lower face intersectingthe lateral face of the self-aligning cusp and having a self aligningfeature; the self-aligning feature comprising an alignment opening andan introduction channel; said alignment opening comprising asemi-cylindrical opening formed in the lower face of the self-aligningcusp; said introduction channel comprising a semi-cylindrical openingformed on the lateral face of the self aligning cusp having an axisorthogonal to the alignment opening and intersecting the alignmentopening and the self-aligning hole; whereby a watchband may be attachedto the watch case by engaging an end of a retractable spring-bar in theplain hole and engaging the opposite end of the spring-bar with thelower surface of the self-aligning cusp until the spring-bar engages thealignment opening, whereupon the spring-bar is retracted to engage theintroduction channel and is moved toward the self-aligning hole until itengages the self-aligning hole to securely attach the watchband to thewatch case.